Train-control system.



G. P. THURBER.

TRAIN CONTROL SYSTEM.

Patented May 4 2 SHEETS-SHEET I. m

alwenfoz GH'oznm Z m 0 2 Y A M D E IL H N W T A c U P DI A GUY P. THURBER, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO AUTOMATIC TRAIN CONTROL & SIGNAL COMPANY, OF PITTSBURGH,

PENNSYLVANIA, A CORPORATION OF DELAWARE.

TRAIN-CONTROL SYSTEM.

Specification of Letters Patent.

Patented May I, 1915.

Application filed May 20, 1912. Serial No. 698,389.

To all whom it may concern:

Be it known that I, GUY P. THURBER, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Train-Control Systems, of which the following is a specification.

This invention relates to the automatic control of railway trains and particularly to the control of the air brakes.

The object of the invention is to automatically control the setting of the brakes upon the happening of certain events, entirely independent of the control exercised by the engineer. The invention for this purpose might be so arranged that when the train passes into a danger zone the brakes will be applied automatically to bring the train to a stop.

One of the principal features of the invention consists of what I have termed an automatic brake valve which is interposed between the engineers valve and the train line and which, when actuated, cuts off communication between the erigineers valve and the train line and provides a means of exhaust from the'train line whereby to cause a setting of the brakes. The operation of this automatic brake valve is preferably controlled by a pressure-actuated device. In addition to the exhaust valve the automatic brake valve is preferably provided with a supplemental exhaust valve which provides an additional means of escape for the train line pressure, and this supplemental exhaust valve is also preferably controlled by a fluid-pressure-actuated device. In accordance with the preferred arrangement the supplemental exhaust valve is normally held closed when th'e'pressure is admitted to the fluid-actuated device controlling the same and the cut-off valve remains open so long as no pressure is admitted to the fluid-pressure-actuated device controlling it.

An additional feature resides in the provision of a valve which is underthe control of the automatic train controlling system, which valve is arranged to control the operation of the automatic brake valve.

Various other-objects and features of the invention will appear as the specification V proceeds.

In the accompanying drawings I have llustrated a preferred embodiment of the invention, but I would have it understood that various changes and modifications may be made without departing from the spirit and scope of the invention.

In the drawings: Figure 1 is a more or less diagrammatic view of a portion of an a1r brake system showing the application of my invention thereto. Fig. 2 is a longitudinal sectional view of the so-called automatic brake valve, showing the parts in their normal position. Fig. 3 is a similar view, showing the parts in the position assumed when an automatic application of the brakes is made. Fig. 4 is a detail sectional View taken on the line 3-3 of Fig. 3. r

The same reference characters refer to like parts throughout the several views.

In Fig. 1, wherein is, shown only so much of an air brake equipment as is necessary to properly illustrate the invention, the train line is indicated at 1 and the engineers valve for controlling pressure in the train line as shown at 2. 3 is the main reservoir which is connected with the engineers valve as indicated. The engineers valve operates in the usual way, a reduction of pressure in the train line accomplished by operation of the engineers valve, causing an application of the brakes in the usual fashion.

Interposed at a point, in the connection 5 between-the engineers valve and the train line I have placed a so-called automatic brake valve 6. Specifically this automatic brake valve consists preferably of a valve casing 7 having a main passage therein connected at one end 8 with the engineers valve and connected at the other end 9 with the train line. The valve 10 controls flow through this main passage and said valve is nected to the train line provides a means of escape for the train line pressure when the valve is in the position shown in Fig. 3. Ordinarily this exhaust passage is closed by the exhaust valve 15. The exhaust valve and the main valve 10 are so arranged that when one is closed the other will be open, and for this reason the exhaust valve is also preferably carried by the valve stem 12. The parts are preferably held in the normal position shown in Fig. 2 by means of a.

spring 16 which forces the exhaust valve closed and holds the cut-01f valve open. When, however, pressure is admitted to the head of the piston through the piping 17, the piston will be forced over so as to close the cut-off valve and open the exhaust valve. This closing of the cut-01f valve prevents any further communication between the engineers valve and the train line, and the opening of the exhaust valve provides a means of escape for the pressure in the train line-the reduction of pressure in the train line thereby accomplished, causing the brakes to be automatically set.

. To further facilitate the automatic application of the brakes, there is preferably provided a supplemental exhaust passage 18 communicating with the same end of the main passage as the first exhaust passage. This supplemental exhaust passage is normally closed by means of a supplemental exhaust exhaust valve 19, and this supplemental exhaust valveis also preferably controlled by a fluid-actuated device, such as the diaphragm 20. The parts are preferably so arranged that when pressure is admitted to the diaphragm 20 the supplemental exhaust valve will be held closed, substantially as shown in Fig. 2. From the foregoing it will be evident that when pressure is admitted to the top of the piston the cut-off valve will be closed and the exhaust valve will be opened, and that when pressure on the diaphragm is relieved the supplemental exhaust valve will be opened and an additional means of escape for the pressure in the train line will be thereby pro-' vided.

The admission of the fluid under pressure to the fluid-actuated device of the automatlc brake valve is controlled by any suitable means. According to the-preferred embodiment-,however, the flow of the actuatmg fluid 1s governed by controlling valve 21, this valve being preferably like the socalled magnet valve disclosed in my pendmg appllcation Serial No. 632,052. This controlling valve is connected by piping 22 w1th the dlaphragm of the automatic brake valve, and by piping 23-'17 with the piston of the automatic brake valve. The controlling valve is also connected by piping 24 with a sourceof fluid-pressure supply, the source 1n this particular instancebeing the train line. In the normal condition of the controlling valve it acts to permit flow of ously described, to cut ofi the engineers valve and release the pressure in the train line to thereby cause an application of the brakes. The controlling valve is itself controlled by any suitable mechanism. Preferably, however, the controlling valve is interposed in and forms a part of the automatic train controlling system, such as disclosed in my co-pending application Serial No. 461,141. The controlling valve when thus included within an automatic train controlling system acts under certain conditions to exercise control over the automatic brake valve to cause a settin of the brakes. Usually the controlling va ve is actuated by the automatic train controlling system when the train enters a danger zone. It will be clear therefore that when such an arrangement, when the train enters a danger zone, the controlling valve will be actuated, thereby causing operation of the automatic brake valve and a consequent application of the brakes.

In addition to the foregoing, it is desirable that previous toor at the time of applying the brakes, the motive power should be cut off. This is provided for in the present instance by the use of a so-called throttle controlling cylinder 25 which, when pressure is admitted thereto through piping 23, acts upon the throttle lever 26 to shut oil the power.

In order that the. engineer may, 1f he realizes the necessity for so doing, assist the automatic brake-setting means in securlng a more rapid application of the brakes, the automatic brake valve is preferably provided with a relief passage 27 forming a bypass around the cut-off valve. This bypass is controlled by check valve 28 to permit passage toward the engineers valve and to prevent flow in the opposite direction. It will be evident, by means of this provision that when the cut-off valve has been closed and the exhaust valve has been opened to cause an automatic application of the I brakes, the engineer may, by throwing his valve to the emergency position provide by way of the relief valve and engineers applied too suddenly the brake shoes are liable to become locked so hard against the Wheels as to cause the wheels to slide on the rails. To overcome this, the custom has been, in making a quick stop, to apply the brakes forcibly and just as the wheels are about to slip, to release them and allow the wheels to take up the motion of the train, and then again apply the brakes. By this alternate application and release of the brakes, much greater braking efiiciency is obtained than if the brakes were simply applied and held on. Another feature of the present invention consists in accomplishing this same braking action by automatic means. And this is done by taking the pressure for operating the fluid-actuated device direct from the train line so that the fluidactuated device while controlling pressure in the train line, will itself in a way be controlled by conditions in the train line. When the controlling valve 21 is operated, the same opens up flow of fluid under pressure from the train line to the top of the piston 11, and the piston is pushed over to close the cut-off valve and open the exhaust valve. Any further supply from the main reservoir is thereby cut 0d and the train line pressure escapes through the exhaust ports. The train lines pressure is the force which is acting on the piston to hold the cut-ofl valve closed and the exhaust valve open, and at this time the train line pressure is being constantly reduced, so there comes a time when the force of the spring 16 overcomes the reduced force of the train line pressure, and shifts the piston back, thereby closin the exhaust valve and openin the cut-o valve.

en the magnet valve 21 is deenergized to admit air from the train line to the head of the piston 11, the cut-ofi' valve 10 is closed and the exhaust valve 15 is opened, and the air gage on the engine shows that there is an immediate drop of from 110 lbs. to 95 lbs. pressure. After a few seconds there is another dro of 10 lbs. to 85 lbs. pressure and after a ew more seconds there is another drop of 5 or 10 lbs. to 7 O or lbs. pressure, in which osition the air gage remains until the bra es are released by closing the magnet valve 21. In this operation it would appear that the air in the train line is suddenly released until there is a balancing of the piston 11, which allows the cut-ofl' and exhaust valves to open and close automatically as the air is balanced and unbalanced, due to the pressure 1n the tram line, until the train line pressure has been reduced to say 65 or -lbs., where 1t remains. The pressure in the tram line 1s therefore gradually reduced, due to the automatic movement of the brake valve piston 11, thus giving a reductlon which will give the best results in operation of the tr What is claimed, is:

1. The combination with the train line of an air brake system, of a normally closed exhaust valve connected with said train line, a fluid-actuated device arranged when acted upon by fluid under pressure to open the exhaust valve, a normally closed supplemental exhaust valve connected with the train line, a fluid-actuated device arranged when acted upon by fluid under pressure to hold the supplemental exhaust valve closed, and means controlling admission of fluid under pressure to the fluid-actuated devices.

2. The combination with the train line of an air brake system and the engineers valve connected with the train line, of a normally open cut-ofl valve interposed between the engineers valve and the train line, a normally closed exhaust valve in communication with the train line, a fluid-actuated device arranged when acted upon by fluid under pressure to hold the exhaust valve closed and the cut-ofl' valve open, a normally closed supplemental exhaust valve connected with the train line, a fluid-actuated device arranged when acted upon by fluid under pressure to hold the supplemental exhaust valve closed, and means controlling admission of fluid under pressure to the fluid actuated devices.

3. The combination with the train line of an air brake system, of a normally closed exhaust valve connected with said train line, a fluid-actuated device arranged when acted upon by fluid under pressure to open the exhaust valve, a normally closed supplemental exhaust valve connected with the train line, a fluid-actuated device arranged when acted upon by fluid under pressure to hold the supplemental exhaust valve closed, and means for simultaneously permitting flow of fluid to the first fluid-actuated device and rediaphragm.

5. The combination with the train line of an air brake system and the engineers valve connected with the train line, of a normally open cut-ofl valve interposed between the engineers valve and the train line, a piston arranged when acted upon by fluid under pressure to close the cut-off valve, 3. normally closed a test valve co with are the train line, a fluid-actuated device ar-' ranged when acted upon by fluid under pressure to hold the exhaust valve closed, and means for simultaneously admitting flow of fluid to the piston and releasing the pres-- upon by fluid under pressure to hold the.

supplemental exhaust valve closed, and means for simultaneously admitting flow of fluid under pressure to the piston and releasing pressure on the fluid-actuated device whereby to close the cut-ofl valve and open the exhaust valve and supplemental exhaust valve.

7 In combination with the train line and engineers valve of an air brake system, a normally open cut-ofl' valve interposed between the engineers valve and the train line, an exhaust valve in communication with the train line, a piston connected with said valves arranged when acted upon by fluid under pressure to hold the cut-off valve closed and the exhaust valve open, a normally closed supplemental exhaust valve connected with the train line, a diaphragm arranged when acted upon by fluid under pressure to hold the supplemental exhaust valve closed, and means for simultaneously admitting fluid to the piston and releasing pressure on the diaphragm whereby to close the cut-off valve and open the exhaust valve and supplemental exhaust valve.

8. In combination with the train line'of an air brake system and an engineers valve controlling pressure in said train line, a normally open cut-ofi valve interposed between the engineers valve and train line, a normally closed exhaust valve incommunication with the train line, a piston connected with said valves arranged when acted upon by fluid under pressure to close the cut-off valve and open the exhaust valve, a normally closed supplemental exhaust valve, a diaphragm arranged when acted upon by fluid under pressure to hold the supplemental exhaust valve closed, a source of fluid under pressure, connections between said source of fluid under pressure and the piston and diaphragm aforesaid, and a compound valve in said connections arranged to normally prevent flow of fluidvto the piston and permit flow of fluid to the diahaust valve connected with the train line,

a piston arranged when acted upon by fluid under pressure to open the exhaust valve, a fluid-actuated train controlling device, a source of fluid under pressure, connections between said source of fluid under pressure and the fluid-actuated train controlling device and the piston aforesaid, and a controlling valve in said connections'arranged when actuated to open up flowof fluid under pressure to the train controlling device and to the piston. I I

' 10'. An automatic brake valve comprising a valve casing having a main passage therein, a valve controlling said main passage, an exhaust passage extending from one end of the main passage, an exhaust valve controlling said exhaustpassage, a fluid-actuated device connected with said valve arranged when acted upon by fluid v under pressure to close the main valve and open the exhaust valve, a supplemental exhaust passage communicating with one end of the main passage, a valve controlling said supplemental exhaust passage, and a fluid-actuated device arranged to be acted upon by fluid under pressure to hold the supplemental exhaust valve closed.

11. An automatic brake valve comprising a valve casing having a main passage therein, a valve controlling said passage, an exhaust passage communicating with one end.

of the mainpassage, a valve controlling said exhaust passage, a piston connected with the main and exhaust valves, arranged when acted upon by fluid under pressure to close the main valve and open the exhaust valve, a supplemental exhaust passage extending from the same end of the main passage as the first exhaust passage, a supplemental exhaust valve controlling the supplemental exhaust passage, and a diaphragm arranged when actedupo'n by fluid under pressure to hold the supplemental exhaust valve closed.

'12. An automatic brakevalve comprising a valve casing having a main passage therein, a cut-oif valve controlling flow through the main passage, an exhaustpassage communicating with one end of the main passage, an exhaust valve controlling the exhaust passage, a fluid-actuated device connectediwith said valves arranged when acted upon by fluid under pressure to hold the cut-01f valve closed and the exhaust valve open, and a by-pass arranged to permit flow betweenthe ends of the main passage when thecut-otLvalve is closed. v

13. An automatic brake valve comprising a valve casing having a main passage there- ,in, a cut-off valve controlling flow through the main passage, an exhaust passage communicating with one end of the main passage, an exhaust valve controlling the exhaust passage, a fluid-actuated device connected with said valve arranged when acted upon by fluid under pressure to hold the cut-off valve closed and the exhaust valve open, a bypass arranged to permit flow between the ends of the main passage when the cut-off valve is closed, a check valve in said bypass, a supplemental exhaust passage communicating with one end of the main passage, a normally closed supplemental exhaust valve controlling said passage, and a fluid-pressure-actuated device controlling operation of said supplemental exhaust valve.

14:. In combination with the train line and engineers valve of an air brake system, a normally open cut-off valve interposed between the engineers valve and the train line, a normally closed exhaust valve in communication with the train line, a fluid-actuated device arranged when acted upon by fluid under pressure to close the cut-off valve and open the exhaust valve, and a relief valve arranged to provide communication between the train line and the engineers valve when the cut-off valve is closed.

15. In combination with the train line and engineers valve of an air brake system, a normally open cut-ofl' valve interposed between the engineers valve and the train line, a normally closed exhaust valve in communication with the train line, means arranged to normally hold the exhaust valve closed and the cut-off valve open, and a relief valve arranged to provide communication between the engineers valve and the train line when the cut-ofl' valve is closed.

16. In combination with the train line and engineers valve of an air brake system, a normally open cut-ofi valve interposed between the engineers valve and the train line, a normally closed exhaust valve in communication with the traiirline a fluidactuated device arran ed to normally hold the exhaust valve closed and the cut-ofl' valve open, and a relief valve arranged to provide communication between the engineers valve and the train line when the cut-ofl' valve is closed. v

17. The combination with the train line of an air brake system and the engineers valve connected with the train line, of a normally open cut-off valve interposed between the engineers valve and the train line, a normally closed exhaust valve interposed between the engineers valve and train line, a fluid-actuated device in connection with said valves and arranged to normally hold the cut-off valve open and the exhaust valve closed, a normally closed supplemental exhaust valve connected with the train line, a fluid-actuated device arranged to normally hold said supplemental exhaust valve closed, and means for controlling flow of actuating fluid to the fluid-actuated devices.

18. In combination with a train line, and engineers valve of an air brake system, a normally open cut-off valve interposed between the engineers valve and the train line, a normally closed exhaust valve in communication with the train line, means arranged to normally hold the exhaust valve closed and the cut-off valve open, a fluidactuated device arranged when acted upon by fluid under pressure to close the cut-off valve and open the exhaust valve, and means for admitting an actuating fluid of varying force to said fluid-actuated device whereby to cause alternate opening and closing operations of the valves aforesaid.

19. In combination with an air brake system including a main reservoir, a train line and an engineers valve interposed between the reservoir and train line for controlling pressure in the train line, of an automatically operated valve in communication with the train line, and means for operating said valve to alternately out oh. the main reservoir and provide escape from the train line, and open up communication with the reservoir and cut off escape from the train line automatically a plurality of times.

20. An air brake system comprising: a reservoir, a train line, a cut-ofl valve and an exhaust valve between the reservoir and the train line, means, which in the absence of pressure normally holds the cut-0E valve open and the exhaust valve closed, means for permitting the pressure in the train line to reverse the position of the valves, whereby the alternate reduction in and building up of pressure in the train line will alternately open and close the valves aforesaid.

21. An air brake system comprising: a reservoir, a cut-ofl' valve for admitting and cutting ofi fluid from the reservoir to the train line, an exhaust valve adapted to be closed when the cut-ofi' valve is open for exhausting pressure from the train line, a fluid actuated device connected to the train line and adapted to close the cut-off valve and open the exhaust valve when acted upon by the train line pressure, means for normally closing communication between the train line and the fluid actuated device, means acting in opposition to the air pressure for moving the fluid actuated device to open the cut-ofi' valve and close the exhaust valve, whereby when train line pressure is once admittedto the fluid actuated device, the cut-0E and exhaust valve will automatically close and open in alternation a plurality of times.

22. An air brake systemoomprising: a

in the train line, and means between the Signed at Pittsburgh; in the county of reservoir and train line under the control Allegheny and State of Pennsylvania, this of the controlling device for alternately ex- 11th day of May, A3). 1912.

hausting fluid from and admitting fluid to GUY P. THURBER; 5 the train line automatically a plurality of Witnesses:

times when influenced by the controlling de- JOSEPH Knox STONE,

v1ce. C. LYNCH. 

